Correct README typo

Author: matt-dray

README.md

@@ -2,7 +2,7 @@
 
 [![Project Status: Concept – Minimal or no implementation has been done yet, or the repository is only intended to be a limited example, demo, or proof-of-concept.](https://www.repostatus.org/badges/latest/concept.svg)](https://www.repostatus.org/#concept)
 
-An app to explore data for Types of Potentially-Mitigable Activity (TPMAs).
+An app to explore data for Types of Potentially-Mitigatable Activity (TPMAs).
 
 The app is [deployed to Posit Connect](https://connect.strategyunitwm.nhs.uk/tpma-explorer/) (login and permissions required).